操作条件对超滤膜运行经济稳定性能的影响

采用正交实验的方法对棕榈油生产废水二级处理出水的超滤工艺条件进行考察和优化,并用膜通量衰减系数、平均跨膜压差及产水量各自加权相加所得综合指标来表征不同超滤操作条件下膜运行的经济稳定性能。正交试验结果表明,减小膜表面流速和产水率,提高处理废水温度均有利于系统经济稳定地运行;各运行参数对综合指标影响的大小顺序为:膜表面平均流速>产水率>温度;在保证出水质量的前提下,最佳组合操作条件为膜表面平均流速0.7m/s,产水率80%,废水温度30℃。     

Integration of biological method and membrane technology in treating palm oil mill e uent

Palm oil industry is the most important agro-industry in Malaysia, but its by-product–palm oil mill e uent (POME), posed a great threat to water environment. In the past decades, several treatment and disposal methods have been proposed and investigated to solve this problem. A two-stage pilot-scale plant was designed and constructed for POME treatment. Anaerobic digestion and aerobic biodegradation constituted the first biological stage, while ultrafiltration (UF) and reverse osmosis (RO) membrane units were combined as the second membrane separation stage. In the anaerobic expanded granular sludge bed (EGSB) reactor, about 43% organic matter in POME was converted into biogas, and COD reduction e ciency reached 93% and 22% in EGSB and the following aerobic reactor, respectively.With the treatment in the first biological stage, suspended solids and oil also decreased to a low degree. All these alleviated the membrane fouling and prolonged the membrane life. In the membrane process unit, almost all the suspended solids were captured by UF membranes, while RO membrane excluded most of the dissolved solids or inorganic salts from RO permeate. After the whole treatment processes, organic matter in POME expressed by BOD and COD was removed almost thoroughly. Suspended solids and color were not detectable in RO permeate any more, and mineral elements only existed in trace amount (except for K and Na). The high-quality e uent was crystal clear and could be used as the boiler feed water.     

膨胀颗粒污泥床-接触氧化法处理棕榈油废水

采用膨胀颗粒污泥床（EGSB）-接触氧化工艺处理棕榈油废水。考察了该工艺对废水COD、固体悬浮物（SS）、有机氮等的去除效果,关键工艺参数,同时探讨了盐浓度对废水生物处理效果的影响。实验结果表明,该组合工艺COD去除率高于95％,BOD,和SS去除率均高于98％,油脂去除率高于90％,有机氮去除率82％,处理后的出水满足马来西亚回灌水国家标准。因出水中含大量的钾,将其用于农田灌溉时,不仅可减少肥料的用量,而且可减少对环境的污染。     

1998-2007年中国棕榈油的贸易地位及进口结构演变

对1998--2007年中国棕榈油的贸易地位、进口品种及进口市场结构进行了实证分析。结果表明,中国棕榈油进口在国内非木质林产品贸易和国际棕榈油市场均占据重要地位,进口市场集中率偏高。151190类棕榈油为中国主要进口品种,151110类棕榈油进口需求呈快速增长趋势。中国棕榈油进口价格风险大,产业安全问题严重。针对这些问题,提出中国棕榈油产业发展的进口多元化、战略储备、活跃本国棕榈油期货市场、发展本国棕榈油产业和海外投资等战略措施。     

Startup and operation of anaerobic EGSB reactor treating palm oil mill effluent

A bench-scale expanded granular sludge bed (EGSB) reactor was applied to the treatment of palm oil mill ettluent (POME).The reactor had been operated continuously at 35℃ for 514 d,with organic loading rate (OLR) increased from 1.45 to 17.5 kg COD/(m3·d).The results showed that the EGSB reactor had good performance in terms of COD removal on the one hand,high COD removal of 91% Was obtained at two days’ of hydraulic retention time (HRT),and the highest OLR of 17.5 kg COD/(m3·d).On the other hand,only 46% COD in raw POME Was transformed into biogas in which the methane content was about 70% (v/v).A 30-d intermittent experiment indicated that the maximum transformation potential of organic matter in raw POME into methane Was 56%.Volatile fatty acid (VFA) accumulation was observed in the later operation stage,and this Was settled by supplementing trace metal elements.On the whole,the system exhibited good stability in terms of acidity and alkalinity.Finally, the operational problems inherent in the laboratory scale experiment and the corresponding countermeasures were also discussed.     

利用棕榈油工艺废水生产单细胞蛋白饲料及其温室气体减排效果

棕榈油工艺废水由于处理难度大,处理成本高,仍然处于靠自然氧化处理的粗放阶段,同时产生大量的温室气体排放。利用微生物发酵技术将POME资源化为单细胞蛋白饲料原料,不仅解决了POME处理的问题,实现经济收益,而且整个处理过程是净负碳足迹的。在全球应对气候变化和资源短缺的背景下,利用食品加工工艺废水生产单细胞蛋白饲料,将成为重要的发展方向。